The present invention relates to a new sulfonamide derivative useful as a metal ion shielding agent.
As a compound of this type, a sulfonamide derivative given by the following formula has been known in the past: ##STR2## (where R represents an aromatic group, and L an alkylene group.) However, none of them is known as a metal ion shielding agent.
When it is attempted to use the compound as a metal ion shielding agent, solubility to water is low, and deposition occurs when the compound is used or it is used as a chelate of metal. This causes problems, for example, when the compound is used as a metal ion shielding agent for photographic processing solution, for chelate titration or for analytical reagents for medical treatment or for medical drugs.
It is an object of the present invention to provide a new sulfonamide derivative useful as a metal ion shielding agent.